Intrasaccular embolic device

ABSTRACT

An intrasaccular device particularly adapted for treating body lumens. The intrasaccular device includes structure that provides a strong framework as well as improved covering across an opening to an aneurysm sac. The intrasaccular device is intended to retain foreign bodies within the aneurysm sac and includes members for accomplishing this objective. The intrasaccular device is also provided with structure that facilitates the alignment of a plurality of devices deployed within the sac.

This application is a divisional of U.S. application Ser. No.09/704,136, filed Oct. 31, 2000, now U.S. Pat. No. 6,589,265.

BACKGROUND OF THE INVENTION

The present invention relates to intravascular repair methods anddevices for treating hollow spaces such as aneurysms, fistulas, andother cavities and lumens within a patient's body, and is particularlysuited for the treatment of intra-cerebral aneurysms of the cerebralvasculature.

The use of intravascular devices for the treatment of aneurysms hasreceived an increasing amount of attention in the past several years asboth the methods and devices available for intravascular procedures havebecome more efficacious. One such method involves the insertion of aforeign body, such as an occlusion coil, within the aneurysm toprecipitate the formation of a clot or thrombus to thereby partially orcompletely occlude the aneurysm and seal off the aneurysm. This methodtypically poses the risk of the coil or ensuing thrombus migrating fromthe aneurysm to the parent artery and causing an undesired blockage.This method is also often limited to the treatment of aneurysms withsmall necks opening into the artery in order to ensure that the foreignbody will remain within the aneurysm.

In another approach, a plug is inserted into the neck of a saccularaneurysm to block off blood flow into the aneurysm. If the plug is notsized correctly it may dislodge from the aneurysm and into the patient'svasculature. In addition, placement of such a plug necessitates robustcontact with the aneurysm, which can cause rupture of the aneurysm andhemorrhaging.

Attempts have also been made to treat both saccular and fusiformaneurysms by deploying grafts within the vasculature and anchoring themon either side of the aneurysm. These grafts typically extend along theentire length of a fusiform aneurysm, or lie across the mouth of asaccular aneurysm, thereby completely blocking off the flow of blood tothe aneurysm and relieving the pressure thereon.

Such graft devices may consist of a tube adapted to be disposed acrossan aneurysm and having a wire woven into one end of the graft that canbe expanded to sealingly engage the vessel wall. The tube is preferablymade of a suitable polyester material. In yet another approach to theproblem, a sheet of resiliently flexible biocompatible material may beemployed. The sheet is rolled upon itself about one of its longitudinaledges and is introduced adjacent to the aneurysm through a catheter tobe expelled and expanded to form a bridge isolating the aneurysm fromthe flow of blood.

Certain other prior art devices contemplate the use of both a graft orstent and foreign bodies, the combination of which are used to repair ananeurysm. In such a system, the foreign bodies are placed within theaneurysm sac and the graft or stent is employed to retain the foreignmaterial within the sac as well as to provide a passage for fluid flow.Due to the complexity of such systems, it is necessary to coordinate thesequence of deployment of the subcomponents of the system. To wit, theforeign bodies must be placed within the aneurysm sac prior to theplacement of the graft or stent. Alternatively, in the event the graftor stent is first implaced at the repair site, the graft or stent mustbe provided with sidewall apertures or spaces through which the foreignmaterial can be advanced to thereafter be placed within the aneurysmsac.

Although potentially successful in such applications as abdominal aorticaneurysms, certain of the prior devices do present a few drawbacks,especially in applications such as intracranial aneurysms. Among themore notable of the difficulties presented is the need to load suchdevices within a very small delivery catheter lumen and advance the samethrough typically tortuous pathways. In addition, the longer the graftemplaced at the repair site the larger the surface area for clotformation and endothelial cell growth, which in extreme situations cancause new complications for the patient. Also, such devices do notembody the ability to be deployed, detached and/or retrieved as would benecessary in the intra-cranial vessels. The risks posed by these devicesincrease in magnitude when the end organ is the brain, with its smallervessel diameters, weaker vessel walls, and increasingly tortuous paths.The devices described above are thus less than ideally suited tointracranial intravascular intervention.

Moreover, any device placed in the parent artery of an intracranialaneurysm runs the risk of occluding perforating side branches. Theseperforators are small, usually less than 200 microns in diameter, andcan be the sole source of blood flow to important tissues of the brain.Presently known devices such as vascular grafts and stents may partiallyor completely block the flow of blood to one or more such perforators,thereby causing clinically significant ischemic strokes.

Accordingly, what has been needed is a device for treating hollow spacesthat has applications within narrow and highly tortuous vasculaturecharacterized by having numerous perforators. The device should embodystructure that not only creates a strong framework across an opening tothe target space, but also should provide effective coverage of theopening. The present invention satisfies these needs.

SUMMARY OF THE INVENTION

Briefly and in general terms, the present invention is directed towarddevices for treating defects in body lumens such as aneurysms. In oneaspect, the devices of the present invention are intended to be placedintrasaccularly (i.e., in the aneurysm). The intrasaccular devicesinclude structure that provides a strong framework as well as improvedcoverage across the neck of an opening such as into an aneurysm.

In another aspect, the intrasaccular device of the present invention iscontemplated to be used in conjunction with foreign bodies such asembolic coils for the purpose of facilitating clotting within ananeurysm sac. The intrasaccular device of the present invention embodiesstructure for retaining the foreign bodies within the aneurysm sac aswell as members for positioning across the opening to the aneurysm sac.

In yet another aspect, the intrasaccular device is formed from amonolithic structure that includes longitudinally extending members. Thelongitudinally extending members enhance the strength and ability of thedevice to retain foreign bodies within an aneurysm sac.

In one presently preferred embodiment, the intrasaccular device isformed from a small diameter tube with longitudinal slots that extendnearly the length of the device. As the ends of the device are movedaxially toward each other, the intrasaccular device assumes a generallyglobe shape with the uncut ends or connecting structure forming poles.The intrasaccular device is self-expanding and is treated to assume theglobe shape when unconstrained.

In other embodiments, the ends of the intrasaccular device of thepresent invention includes three or more arms extending from a pole. Itis also contemplated that at least at one of the ends of the device, themembers define a cruciform shape or assume a spiral configuration andthat further includes connecting structure in the form of aperpendicular cylindrical nub at an intersection of the members. Instill further embodiments, the connecting structure or nubs at the endsof the device are intended to be inverted. It is also contemplated thatonly one end of the intrasaccular device of the present inventionincludes such connecting structure.

One or more of the intrasaccular devices may be deployed within anopening such as an aneurysm sac. At least one of the polar regions ofthe device are configured to occupy radial space within an entrance tothe aneurysm sac as well as embody structure for aligning multipledevices within the sac.

These and other objects and advantages of the invention will becomeapparent from the following more detailed description, when taken inconjunction with the accompanying drawings of illustrative embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a compressed intrasaccular device of thepresent invention, depicting a tube with longitudinal slits formedtherein;

FIG. 2 is a side view, depicting the device of FIG. 1 in an expandedconfiguration;

FIG. 3 is a side view, depicting a constrained form of an alternativeembodiment of the intrasaccular device of the present invention;

FIG. 4 is a side view, depicting the device of FIG. 3 in an expandedstate;

FIG. 5 is a side view, depicting the device of FIG. 3 in an invertedassembled state;

FIG. 6 is a side view, depicting the device of FIG. 4 in a deformedstate with a recessed nub;

FIG. 7 is a partial end view, depicting wavy members defining anintrasaccular device of the present invention;

FIG. 8 is a partial end view, depicting one manner of folding members ofan intrasaccular device of the present invention;

FIG. 9 is a partial end view, depicting members of an intrasacculardevice of the present invention configured into a spiral;

FIG. 10 is a side view, depicting an alternative embodiment of anintrasaccular device of the present invention.

FIG. 11 is a side view, depicting a shaping mandrel;

FIG. 12 is a side view, depicting one embodiment of an intrasacculardevice of the present invention being manufactured using the shapingmandrel of FIG. 11;

FIG. 13 is a side view partially in cross-section, depicting a deliverycatheter containing one embodiment of the intrasaccular device of thepresent invention, the combination positioned adjacent a repair site;

FIG. 14 is a side view partially in cross-section, depicting theintrasaccular device of FIG. 13 being deployed at the repair site;

FIG. 15 is a side view partially in cross-section, depicting the deviceof FIG. 14 after deployment at the repair site; and

FIG. 16 is a bottom view of an opening to a repair site, depicting aplurality of aligned intrasaccular devices.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, and specifically to FIGS. 1 and 2, thereis shown one embodiment of an intrasaccular device of the presentinvention. The intrasaccular device of the present invention isparticularly suited for treating hollow spaces found within a patient'sbody. In particular, the intrasaccular devices are adapted forfacilitating the repair of aneurysms formed in sidewalls of vasculatureas well as at bifurcations or terminal ends of vasculature. The devicesinclude structure that provides an effective framework and coverageacross an opening to the aneurysm sac. Moreover, due to their noveldesign, the intrasaccular devices of the present invention are useful intreating highly tortuous and narrow vasculature such as theneurovasculature.

In one aspect of the present invention, intrasaccular device 20 has amonolithic body formed from a tube 22. The tube 22 has a plurality ofparallel slits or slots 24 extending longitudinally substantially thelength of the tube 22. End portions 26, 28 of the tube do not includeslits 24.

The intrasaccular device 20 is contemplated to be composed of heatsetable resilient material such that in its unconstrained state, thedevice 20 assumes an expanded configuration. That is, as the ends 26, 28of the device are brought axially closer to each other, a midsection 30of the intrasaccular device 20 increases in diameter. In one presentlypreferred embodiment, the midsection 30 of the intrasaccular device 20assumes a generally spherical or globe-shaped cage with the ends 26, 28defining poles or perpendicular cylindrical nubs 32. Although theFigures depict a device having a midsection cage 30 with fourlongitudinally extending members, as few as three or six or more members34 are contemplated.

As will be developed in more detail below, the constrained tubular shapeas well as the self-expandable nature of the intrasaccular device 20provides a number of advantages. In particular, when compressed into atubular configuration, the device 20 can be placed within a simple smalldiameter delivery catheter for advancement within the vasculature. Uponreaching a repair site, the intravascular device 20 is deployed throughthe delivery catheter and allowed to self-expand at the target site to adesired degree, thereby generally assuming the shape of the cavity atthe repair site.

In another aspect of the invention (FIGS. 3-6), the intrasaccular device20 is formed from a tube 40 that has a plurality of longitudinallyextending arms 42 cut into the tube 40. The arms 42 can have varyinglengths and widths depending upon the intended application or may haveequal lengths and widths. At a terminal end 44 of the arms 40, there maybe configured an enlarged cross-sectional area 46. The enlarged ends 46facilitate reducing “point pressure” and thereby may reduce trauma tovasculature. Staggering the enlarged ends 46 can also allow for betterpacking. The enlarged area 46 may further include apertures 47 centeredtherein. The apertures 47 are intended to aid in manufacturing certainembodiments of a cage midsection portion and reduce possible trauma. Theends can also be configured with platinum marker coils (not shown). Eacharm 40 projects longitudinally from an uncut portion 48 of the tube 40.The uncut portion 48 forms connecting structure in the form of a pole orperpendicular cylindrical nub 50.

As with the previous described embodiment, the assembled form of thissecond embodiment of the intrasaccular device 20 includes a midsection52 that assumes an expanded configuration when unconstrained. As such,the device is self-expandable. A generally cylindrical or a globe-shapedmidsection 52 is desirable for certain applications, however, othershapes may be employed for a particular purpose. Thus, the intrasacculardevice 20 is heat set to achieve the desired expanded configuration.

In a presently preferred embodiment (FIG. 4), the midsection 52 can bedefined by four curved arms 42 forming a cage 56. The cage 56 is boundedon one end by connecting structure or the cylindrical nub 50 and at theother by the terminal ends 46 of the arms 42. The terminal ends 46 maybe affixed to one another or alternatively, the ends can remain freefloating but generally arranged in close proximity. As before, thedevice 20 can be constrained to assume a generally tubular profile foradvancement through and delivery within vasculature at a repair site.

With specific reference to FIG. 5, it is to be understood that incertain circumstances, it may be desirable to configure theintrasaccular device 20 such that it embodies an inverted nubarrangement 60. That is, rather than projecting longitudinally from theconnecting structure or nub 50 in a continuous manner, the arms 42 areheat-set so that they each reverse direction and enclose the nub 50within a first end 62 of a cage 64 defined by the arms 42. Terminal endportions 66 of each arm include a second reversal of direction 68 tocomplete the midsection cage 64. In the event the device 20 includesfree ends, a fixation device 70 is provided to retain the terminal ends60 of the arms 42 in close proximity. Alternatively, the fixation device70 can be defined or replaced by a second nub having structure similarto nub 50.

As shown in FIG. 6, it may also be necessary to recess the connectingstructure or nub 50 to provide a desired end profile. To wit, the arms42 are heat-set so that they are routed through a first reversal ofdirection 70 where the arms 42 immediately extend from the nub 50. Thefirst reversal of direction defines a recess 72 about the cylindricalnub 50. The arms are then formed to assume a second reversal ofdirection 74 to thereby form an S-shape with the first reversal ofdirection and to provide a base portion 74 of a midsection cage 78adjacent the cylindrical nub 50. The arms 42 continue to extend in acurved fashion to define a generally spherical or a globe-shaped cage78.

With reference to FIGS. 7-9, there are various forms that the members 42defining the midsection cage of an intrasaccular device 20 can assume.It is contemplated that the members 42 can include edges 80characterized by waves. Such waves may enhance the flexibility of themember 42 as well as its capacity to retain foreign bodies within ananeurysm sac. In this or other contemplated embodiments, the terminalends 46 of the members, as stated, can be affixed to each other as shownin FIG. 8 by a simple spot weld which is used to form a “tri-fold” ofarms extending from the connecting structure or nub 50. Additionally, asshown in FIG. 9, the members 42 can assume a clockwise orcounterclockwise spiral configuration, to thereby provide a cruciformarrangement that is particularly suited for retaining foreign bodieswithin a cavity. By combining a device that embodies clockwise spiralswith a device that embodies counterclockwise spirals, a crossing mesh isformed.

Another presently preferred embodiment of the intrasaccular device 20 ofthe present invention is shown in FIG. 10. In this embodiment, themembers 42 project in a spiral fashion from the cylindrical nub 50. Thespiral configuration defines a first portion 90 of a cage 92. The secondportion 94 of the cage 92 is defined by curvilinear but generallylongitudinally straight or non-spiral portions 98. A generally closedend 100 of the device is formed by the terminal ends of the members 42.The cage 92 of this embodiment is also self-expanding and defines asubstantially spherical or globe-shape. The cage can include three tosix or more members depending upon the application. When constrained,the device can assume a relatively small diameter profile for loadinginto a delivery catheter.

As stated, the intrasaccular device 20 of the present invention isheat-set so that the cage midsection assumes a desired profile. It iscontemplated that the cage can assume conical, cylindrical as well asother complex forms in addition to a generally spherical shape.Acceptable materials for the intrasaccular device 20 include nitinol,platinum, stainless steel, Eligloy or acceptable polymers or otherhighly elastic materials. Although it is contemplated that theintrasaccular device 20 be manufactured from a tube using such methodsas laser cutting, it is also possible to fabricate the device from aflat sheet, which is then rolled to form a cylindrical nub at least atone end of the device. Moreover, it is additionally contemplated thatthe intrasaccular device can be coated or covered with a membraneforming polymer that can assist in excluding blood flow. As such, a webmay be formed between each or selected members defining theintrasaccular device.

Once a desired pattern for the intrasaccular device is manufactured, thepattern can be placed upon a forming apparatus 110 (FIGS. 11-12). Theforming apparatus 110 may have a spherical shape when it is desired thatthe resultant intrasaccular device 20 be spherical or may have othershapes depending upon the contemplated application. The formingapparatus 110 includes locating pins 112 and forming pins 114. It is tobe recognized that the positions of the locating and forming pins 112,114 can be arranged in various ways to achieve a desired result. The nub50 of the intrasaccular device being fabricated is placed on a locatingpin 112 and arms 42 are deformed about the forming pins 114. The formingpins 114 are positioned on the forming apparatus 110 to aid inconsistently and repeatedly deforming the arms 42 to thereby create adesired midsection cage. The forming apparatus 110 with theintrasaccular device 20 mounted thereon is then subjected to heattreating to set the desired shape.

In use, an intrasaccular device 20 of the present invention may beimplaced at a repair site using a delivery catheter 120 (See FIGS.13-16). The delivery catheter 130 may be composed of a simple flexible,elongate tube having an internal bore or lumen 122. The intrasacculardevice 20 is compressed to a reduced diameter and inserted within theinternal bore 122 of the delivery catheter 120 proximate a terminal endportion 124 of the delivery catheter 120. The terminal end portion 124may be curved to aid in successfully orienting the intrasaccular device20 at the repair site. Additionally, radiopaque markers (not shown) maybe employed to facilitate placement of the delivery catheter proximatethe desired target. Such markers are contemplated to be placed at theterminal ends of the arms of the device 20 or attached or formed as partof the nub thereof.

The intrasaccular device 20 may be releasably attached by conventionalmeans such as a fracturable weld to a pusher member 130. Alternatively,the pusher member 130 can be disconnected from the intrasaccular device120 and include an enlarged pusher head 132 for engaging an inferior endof the-intrasaccular device 20. In either case, the pusher member 130and pusher head 132 have an exterior profile adapted for being slidablyreceived within the lumen 122 of the delivery catheter 120.

Once an aneurysm or other open space 134 is diagnosed as existing withina body, the delivery catheter 120 is placed within the subject'svasculature 136. Conventional methods such as the Seldinger technique isused to gain access to the patient's vasculature. The intrasacculardevice assembly is then advanced through the delivery catheter withinthe patient's vasculature and to the repair site.

At the repair site, the delivery catheter 120 is manipulated so that itsterminal end portion 124 is adjacent an entrance or opening 138 to therepair site 134. The pusher member 130 is then advanced while holdingthe delivery catheter 120 stationary. This action causes theintrasaccular device 20 to advance within the delivery catheter 120toward the terminal end portion 124 of the delivery catheter 120.Alternatively, the catheter is placed at the aneurysm and the device 20is “unsheathed” by retracting the catheter while holding position withthe delivery wire.

The pusher 130 is moved longitudinally until the intrasaccular device 20is deployed from the terminal end portion 124 of the delivery catheter120 and within the repair site 134. As the intrasaccular device 20 isejected from the delivery catheter 120, the midsection of theintrasaccular device self-expands to thereby substantially conform tothe interior geometry of the saccular repair site. In the event theintrasaccular device 20 is releasably attached to the pusher member 130,action is taken to break the connection. Otherwise, the pusher member130 is simply advanced until the intrasaccular device 20 hasself-expanded within the repair site 134.

When positioned within the repair site 134, the nub 50 of anintrasaccular device is oriented within the opening 138 to the repairsite 134. Thereafter, additional intrasaccular devices 20 can besimilarly placed within the saccular repair site 134. As specificallyshown in FIG. 16, the connecting structure in the form of nubs or poles50 of the plurality of intrasaccular devices 20 cooperate in aligningadjacent members 42 defining the intrasaccular device 20. The members 42themselves additionally provide a strong framework across the opening138 through the repair site 134. Moreover, where an embodiment of theintrasaccular device 20 embodies spirally oriented members in oppositedirections for example, an increased amount of coverage across anentrance to the repair site is provided.

Upon successfully delivering the desired number of intrasaccular devices20 at a repair site, coils (not shown), embolic material, or otherforeign bodies may be placed within the repair site to aid in clottingthe area. Such material can be inserted through adjacent members 42defining the intrasaccular device 20. Additional intrasaccular devices20 may then be placed within the repair site if desired. It is to berecognized, however, that the intrasaccular devices themselves may berelied upon to create thrombosis or change the flow path of blood. Assuch, it may not be necessary to use the intrasaccular devices 20 incombination with coils or other bodies in every situation.

Thus, the present invention is useful in providing an improved systemfor repairing abnormalities existing within vasculature. Due to itsability to be compressed into a small profile and subsequentlyself-expand to provide a framework across an opening to the repair site,the present invention is particularly suited for repairing very distaland tortuous vasculature.

It will be apparent from the foregoing that, while particular forms ofthe invention have been illustrated and described, various modificationscan be made without departing from the spirit and scope of theinvention. Accordingly, it is not intended that the invention belimited, except as by the appended claims.

1. A system for treating a saccular cavity of a patient, comprising: afirst intrasaccular device, the first intrasaccular device having afirst set of members configured into a clockwise spiral; a secondintrasaccular device formed separately and defining structure separateand distinct from the first intrasaccular device, the secondintrasaccular device having a second set of members configured into acounterclockwise spiral; a non-attaching configuration wherein in saidnon-attaching configuration the first and second intrasaccular devicesare separate and non-attached to each other; an attaching configurationwherein in said attaching configuration the first and secondintrasaccular devices cooperate to form a crossing mesh pattern; andwherein the first and second intrasaccular devices are configured to beseparately and unconnectedly delivered to the saccular cavity.
 2. Thesystem of claim 1, wherein each of first and second intrasacculardevices include a body.
 3. The system of claim 2, wherein the body isself expandable.
 4. The system of claim 1, the first intrasacculardevice further including a first end, a second end and a midsection. 5.The system of claim 4, the first intrasaccular device further includinga first connecting structure formed at the second end.
 6. The system ofclaim 5, the second intrasaccular device further including a firstconnecting structure formed at the second end.
 7. The system of claim 6,the second intrasaccular device further including a second connectingstructure formed at the second end.
 8. The system of claim 7, whereinthe first and second connecting structures cooperate to facilitate aneven distribution within the saccular cavity.
 9. The system of claim 1,wherein the first intrasaccular device is formed from a monolithicstructure.
 10. The system of claim 1, wherein the second intrasacculardevice is formed from a monolithic structure.
 11. The system of claim 1,wherein each of the first and second intrasaccular devices are formedfrom monolithic structures.
 12. The system of claim 1, wherein the firstintrasaccular device defines a generally spherical shape.
 13. The systemof claim 1, wherein the second intrasaccular device defines a generallyspherical shape.
 14. The system of claim 1, wherein the first and secondintrasaccular devices each define a generally spherical shape.
 15. Thesystem of claim 1, further comprising a catheter and the first andsecond intrasaccular devices can each assume a compressed configurationand an expanded configuration.
 16. The system of claim 15, wherein thecatheter retains the first and second intrasaccular devices in thecompressed configuration.